Question

您好我使用RBloomberg库返回了以下数据帧：

> tt <- bdh(conn, secs, "last price", "20110501")
> tt
          ticker       date last price
1  EURUSD Curncy 2011-05-01         NA
2  EURUSD Curncy 2011-05-02     1.4830
3  EURUSD Curncy 2011-05-03     1.4825
4  EURUSD Curncy 2011-05-04     1.4827
5  EURUSD Curncy 2011-05-05     1.4539
6  EURUSD Curncy 2011-05-06     1.4316
7  EURUSD Curncy 2011-05-07         NA
8  EURUSD Curncy 2011-05-08         NA
9  USDZAR Curncy 2011-05-01         NA
10 USDZAR Curncy 2011-05-02     6.6090
11 USDZAR Curncy 2011-05-03     6.6394
12 USDZAR Curncy 2011-05-04     6.6837
13 USDZAR Curncy 2011-05-05     6.7250
14 USDZAR Curncy 2011-05-06     6.7051
15 USDZAR Curncy 2011-05-07         NA
16 USDZAR Curncy 2011-05-08         NA
17 USDTRY Curncy 2011-05-01         NA
18 USDTRY Curncy 2011-05-02     1.5218
19 USDTRY Curncy 2011-05-03     1.5336
20 USDTRY Curncy 2011-05-04     1.5471
21 USDTRY Curncy 2011-05-05     1.5488
22 USDTRY Curncy 2011-05-06     1.5445
23 USDTRY Curncy 2011-05-07         NA
24 USDTRY Curncy 2011-05-08         NA
25 USDBRL Curncy 2011-05-01         NA
26 USDBRL Curncy 2011-05-02     1.5893
27 USDBRL Curncy 2011-05-03     1.5876
28 USDBRL Curncy 2011-05-04     1.6182
29 USDBRL Curncy 2011-05-05     1.6220
30 USDBRL Curncy 2011-05-06     1.6149
31 USDBRL Curncy 2011-05-07         NA
32 USDBRL Curncy 2011-05-08         NA
33 USDINR Curncy 2011-05-01         NA
34 USDINR Curncy 2011-05-02    44.3350
35 USDINR Curncy 2011-05-03    44.5150
36 USDINR Curncy 2011-05-04    44.4675
37 USDINR Curncy 2011-05-05    44.7625
38 USDINR Curncy 2011-05-06    44.7950
39 USDINR Curncy 2011-05-07         NA
40 USDINR Curncy 2011-05-08         NA

如何将其变成看起来更像是这样的东西（即自动收录列值已成为列名）？

Date    EURUSD Curncy   USDZAR Curncy   USDTRY Curncy   USDBRL Curncy   USDINR Curncy
2011-05-01          NA          NA          NA          NA          NA
2011-05-02      1.4830      6.6090      1.5218      1.5893     44.3350
2011-05-03      1.4825      6.6394      1.5336      1.5876     44.5150
2011-05-04      1.4827      6.6837      1.5471      1.6182     44.4675
2011-05-05      1.4539      6.7250      1.5488      1.6220     44.7625
2011-05-06      1.4316      6.7051      1.5445      1.6149     44.7950
2011-05-07          NA          NA          NA          NA          NA
2011-05-08          NA          NA          NA          NA          NA

Answer 1

查看包dcast中的reshape2功能：

library(reshape2)
dcast(tt, date ~ ticker)


        date EURUSD USDBRL  USDINR USDTRY USDZAR
1 2011-05-01     NA     NA      NA     NA     NA
2 2011-05-02 1.4830 1.5893 44.3350 1.5218 6.6090
3 2011-05-03 1.4825 1.5876 44.5150 1.5336 6.6394
4 2011-05-04 1.4827 1.6182 44.4675 1.5471 6.6837
5 2011-05-05 1.4539 1.6220 44.7625 1.5488 6.7250
6 2011-05-06 1.4316 1.6149 44.7950 1.5445 6.7051
7 2011-05-07     NA     NA      NA     NA     NA
8 2011-05-08     NA     NA      NA     NA     NA

Answer 2

我想到的是使用tapply：

tapply(tt$price, list(date=tt$date, ticker=tt$ticker), mean)

因为一个元素的平均值是元素本身，所以它应该是相同的。一旦你有一天以上的价值和自动收报机，你只会遇到麻烦。（但是，你的要求没有明确定义）

将字段值转换为R数据框中的列名

2 个答案: